Honda BF40D Mode D'emploi page 431

4) HO2S heater line short-circuit inspection
a. Turn the combination switch OFF and connect the
HO2S 4P connector
18
b. Disconnect the ECM connector B
continuity between the ECM connector B
wire harness side No.10 (Black/White) terminal and
the engine ground.
ECM CONNECTOR B
MAIN WIRE HARNESS SIDE
10
VIEWED FROM THE TERMINAL SIDE
Is there continuity?
YES - Repair short in the main wire harness
between the ECM and the HO2S.
NO - Go to "5) HO2S heater line open-circuit
inspection."
5) HO2S heater line open-circuit inspection
• Turn the combination switch ON. Measure the
voltage between the ECM connector B
wire harness side No.10 (Black/White) terminal and
the engine ground.
ECM CONNECTOR B
MAIN WIRE HARNESS SIDE
10
VIEWED FROM THE TERMINAL SIDE
Is there the battery voltage?
YES - Replace the ECM with a new one and
recheck.
NO - Repair open in the main wire harness
between the ECM and the HO2S.
.
. Check for
10
main
10
O2HT (Black/White)
main
10
O2HT (Black/White)
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